Technical and Economic Evaluation of Efficiency Improvement after Rewinding in Low-Power Induction Motors: A Brazilian Case

Abstract

Nowadays the economic analysis of an induction motor's life cycle is the clearest way to measure the viability of actions to promote energy-efficient technologies to the end user. The cost effectiveness in motors replacement by energy-efficient motors is a well-known practice that leads to energy savings, however this paper presents the cost-effectiveness of low-power induction motors which have their efficiency improved after rewinding. This process improves the investment viability and brings the greatest financial and energetic savings. In this paper, low-power induction motors are rewound and their efficiencies are measured by tests A and B from IEEE standard 112/2017. The rewound motors have better cost-effectiveness than replacement by IE3/Premium and even IE4/Super-Premium units. The rewound motors increase between 3 and 4 percentage points in relation to former efficiency and the payback is less than 2 years, regardless of the efficiency measurement method.

A Performance Evaluation of Three-Phase Induction Electric Motors between 1945 and 2020

“…Low acquisition and maintenance cost compared to competing technologies; [22][23][24] The simple constructive characteristics make its manufacture simple compared to competing technologies; [25,26] Simple replacement due to a high degree of standardization of housings and connections; [27,28] Long service life; [29,30] A high degree of speed control using the variable speed drive (VSD), also enabling the saving of electrical energy; [31,32] Small dimensions can be used in compact places; [33] Does not produce sparking, making it easier to apply in classified areas (Ex areas); [34][35][36] High starting torque compared to other competing technologies; [25,26] Quiet compared to competing technologies; [37][38][39] There is no electrical contact between the rotor and the stator; the connection is made only by the bearings, thus giving high operating safety; [25,26] They can be powered directly by alternating current without the need for electronic converters; [25,26] Easy detection of faults of various natures (electrical, mechanical, thermal, and environmental) [40][41][42][43] Known production chain and easy access to the mineral resources necessary for the construction of SCIMs. They do not depend on high-volatility materials in the supply chain, such as, for example, the rare earth magnets present in permanent magnet synchronous electric motors (PMSMs).…”

Voltage Harmonic Impacts on Electric Motors: A Comparison between IE2, IE3 and IE4 Induction Motor Classes

“…Induction motors comparison [2,3,16,[18][19][20]22,25,34,35,37,38] Harmonics impacts on induction motors [5,6,22,[34][35][36]39-44] Harmonics presence and diagnosis in power systems [11,12,44] Fault diagnosis in induction motors [10,13,14] Economic substitution studies [16,23] Line start permanent magnet motor (LSPMM) [5,17,18,21,22,[24][25][26][27][28]31,32,43,[45][46][47][48][49][50][51] Temperature increase due to harmonics [3,5,[34]…”

“…An analysis of the technical and economic benefits of substitution between these technologies has been presented in [2,3,[16][17][18][19][20][21][22][23]. In addition, the studies in [17,18,21,22,[24][25][26][27][28][29][30][31][32] include the main constructive characteristics, weaknesses and strengths related to the LSPMM.…”

Economic evaluation of induction motor based on motor’s nameplate data and initial cost

“…The operational costs, payback period, annual saving in energy, and economic study, in case of single-phase IM is rewound for a three-phase operation are discussed [13]. The economics of IM, planning maintenance, cost-Int J Pow Elec & Dri Syst ISSN: 2088-8694  Economic evaluation of induction motor based on motor's nameplate data … (Mohammed Baniyounis) 1341 effectiveness, and energy savings by using a cost model as in [14], [15]. The economic efficiency and load condition effects considering the IM life-cycle cost are introduced [16].…”